Consciousness and Altered States of Consciousness

Our lives involve regular, dramatic changes in our awareness.
Internal stimuli include pain, hunger, thirst, sleepiness, and awareness of thoughts and emotions.
External stimuli include seeing lights, feeling warmth, or hearing a voice.
Consciousness exists on a continuum ranging from full awareness to deep sleep.
- Other stages include daydreaming, intoxication, and unconsciousness due to anesthesia.
Sleep is characterized by low levels of activity and reduced sensory awareness.

Many biological cycles are short.
The sleep-wake cycle, along with heart rate, blood sugar, and body temperature, are driven by biological rhythms.
The hypothalamus is in charge of the biological clock.
- It is located above the pituitary gland.
- It seeks homeostasis.
Melatonin, released by the pineal gland, possibly regulates many biological rhythms and the immune system during sleep.
Differing sleep patterns are responsible for the difference between